Walter dawson



(No Model.)

W. DAWSON.

LOGOMOTIVE BOILER.

. Patented Sept. 7, 1886.

UNITED STATES PATENT ()rrlcn.

VALTER DAVSON, OF SGRAN'ION, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO\VILLIAM F. HALLSTEAD, OF SAME PLACE.

LOCOMOTlVE-BOILER.

SPECIFICATION forming pan: of Letters Patent No. 348,831, datedSeptember '7, 1886.

Application filed June 8, 1886. Serial No. 204,500. (No model.)

To all whom it may concern:

Be it known that I, TALTER Dawson, of Scranton, in the county ofLackawanna and State of Pennsylvania, have invented certain new anduseful Improvements in Locomotive or, other Boilers, of which thefollowing is a specification, reference being had to the aceompanyin gdrawings,and to the letters of reference marked thereon.

The object of my invention is to construct a boiler specially adapted toburn pulverized fuel, waste coal, culm, &c., although other fuel may beused to advantage, the invention consisting in the construction,combination, I 5 and arrangement of parts, as hereinafter claimed.

In the accompanying drawings, Figure 1 is a front View, partly insection, of a locomotive-boiler embodying my improvements. Fig. 2 is alongitudinal section of the same.

Similar letters of reference indicate similar parts in both figures.

A is the shell or waist of the boiler. represent tubes such as areordinarily used in boilers of this class.

C is the fire-box, and D its tube-sheet. E represents a tubular grateconnecting the front and rear water-spaces of the furnace.

F F represent the lower series of tubes. 0 Theinner or furnace ends ofsaid series oftubes unite with the tube-sheet D, the said tubes havinghere the same diameter as have the tubes B-say two inches. The oppositeend of each tube F, where it connects with the for- 5 ward tube-sheet,D, asiudeed the entire length of the tube, except at the point of itsconnection with the furnace tube-sheet, is enlarged to a diameter of,say, four inches. The object of this construction is threefold, first,to provide a space, as from a to a, for the fuel; sec 0 ondly, toproduce a wide or enlarged space, b, through which an unobstructed andsufficient circulation of water may pass, and thus pro tect the boilerat a point exposed to a high degree of heat; and, thirdly, to bring thetube- 5 surface in as close proximity to the lower portion of the shellor waist of the boiler as is practicable, and thus effectually heat thewa t-er occupying said part of the shell.

In boilers as ordinarily constructed there is a large space at thebottom of the waist or shell, which contains water comparatively cold,because the tube-surface does not extend into it. Consequently no heatis imparted to a large bodyofwater. By myimprovementthis body of wateris effectually heated, the steaming qualities ofthe boiler beingimproved, and its durability increased, owing to the production of auniform temperature.

Having described my invention, I claim In a locomotive or other boiler,the combi' nation, with a shell, furnace-grate, and tube sheets D D, ofa tube, (or series of tubes,)F, arranged throughout the greater part ofits length in close proximity to the shell, and of reduced diameter orsize where it connects with the tube-sheet D, substantially as setforth.

In testimony whereof I have hereunto set my hand and seal.

\VALTEB DAWSON. [L. s] lVitnesses:

JosEPH-A. Morr, MosEs E. CLIFFORD.

